1. Field of the Invention
The present invention relates to an electronic part testing apparatus for testing the connectability of a wiring pattern of an electronic part such as an MCM (multi-chip module), a PGA (pin-grid array) package, a BGA (ball-grid array) package, etc., and it also relates to an electric connecting member which can be used for various electronic devices including an electronic part testing apparatus, for electrical connection between a circuit substrate and an electronic part or between electronic parts.
2. Description of the Related Art
An electronic part such as an MCM (multi-chip module), a PGA (pin-grid array) package, a BGA (ball-grid array) package, etc. includes a plurality of test terminal pins (hereinafter referred to as xe2x80x9ctest pinsxe2x80x9d) for testing connections to the wiring pattern, a plurality of test control input/output terminal pins (hereinafter referred to as xe2x80x9ccontrol pinsxe2x80x9d), and a boundary scanning circuit for observing a result of the test, by independently controlling the voltage of test pins via the control pins. The test of the connectability of the wiring pattern of the electronic part is carried out prior to the shipment of the electronic part or at the time of maintenance. The electronic part testing apparatus includes an adapter for carrying out this test. A conventional adapter is explained with reference to FIGS. 11 to 14.
As shown in FIG. 11, an electronic circuit testing adapter xe2x80x9cnxe2x80x9d (hereinafter referred to as an xe2x80x9cadapterxe2x80x9d) is made of an electrically insulating material such as a resin, and has holes at positions corresponding to test pins xe2x80x9cdxe2x80x9d of an electronic part xe2x80x9cgxe2x80x9d to be tested and holes at positions corresponding to positions of control pins xe2x80x9ccxe2x80x9d. First connecting members or assemblies xe2x80x9c1xe2x80x9d for electrical connection with the control pins xe2x80x9ccxe2x80x9d and second connecting members or assemblies 2 for electrical connection with the test pins xe2x80x9cdxe2x80x9d are disposed in the corresponding holes. The upper surface of each first connecting member 1 projects above the surface of the adapter xe2x80x9cnxe2x80x9d. The first and second connecting members 1 and 2 have contact portions 1a and 2a on the lower surface of the adapter xe2x80x9cnxe2x80x9d, respectively.
Further, below the adapter xe2x80x9cnxe2x80x9d, there is disposed a testing substrate xe2x80x9cexe2x80x9d having pads xe2x80x9chxe2x80x9d corresponding to the contact portions 1a and pad xe2x80x9cixe2x80x9d corresponding to the contact portions 2a. The connecting member 2 is in contact with the pad xe2x80x9cixe2x80x9d at the contact portion 2a. All the pads xe2x80x9cixe2x80x9d are short-circuited by a short-circuit layer xe2x80x9ckxe2x80x9d within the testing substrate xe2x80x9cexe2x80x9d. Further, the connecting member 1 is in contact with the pad xe2x80x9chxe2x80x9d at the contact portion 1a, and all the pads xe2x80x9chxe2x80x9d are independently connected to the connector xe2x80x9cfxe2x80x9d of the testing substrate xe2x80x9cdxe2x80x9d in a predetermined pattern within the testing substrate xe2x80x9cexe2x80x9d.
A test procedure will be explained next. First, a positioning member xe2x80x9cjxe2x80x9d for positioning the electronic part xe2x80x9cgxe2x80x9d and the adapter xe2x80x9cnxe2x80x9d having the above-described circuits is disposed on the outside of the adapter xe2x80x9cnxe2x80x9d. After the electronic part xe2x80x9cgxe2x80x9d is positioned and fixed to the positioning member j, the electronic part xe2x80x9cgxe2x80x9d and the positioning member xe2x80x9cjxe2x80x9d are pressed downward while matching guide pins xe2x80x9cpxe2x80x9d of the positioning member xe2x80x9cjxe2x80x9d with positioning holes xe2x80x9cmxe2x80x9d of the adapter xe2x80x9cnxe2x80x9d. Then, the guide pins xe2x80x9cpxe2x80x9d are inserted into the positioning holes xe2x80x9cmxe2x80x9d, and the control pins xe2x80x9ccxe2x80x9d are brought into contact with the connecting members 1 that are stretched above the upper surface of the adapter xe2x80x9cnxe2x80x9d. When the electronic part xe2x80x9cgxe2x80x9d and the positioning member xe2x80x9cjxe2x80x9d are further pressed downward, as shown in FIG. 12, the connecting members 1 move downward while compressing coil springs in the adapter xe2x80x9cnxe2x80x9d, and stop. At this time, the test pins xe2x80x9cdxe2x80x9d are not brought into contact with the connecting members 2, and are in a released state. In this state, a voltage is applied to the control pins xe2x80x9ccxe2x80x9d of the electronic part xe2x80x9cgxe2x80x9d from a main testing part (not shown) via the connector xe2x80x9cfxe2x80x9d to test for the electrical short-circuiting of the test pins xe2x80x9cdxe2x80x9d (a test state at step 1).
When the electronic part xe2x80x9cgxe2x80x9d and the positioning member xe2x80x9cjxe2x80x9d are further pressed downward, as shown in FIG. 13, the connecting members 1 are pressed in the adapter xe2x80x9cnxe2x80x9d while keeping a connection with the control pins xe2x80x9ccxe2x80x9d. At this time, the test pins xe2x80x9cdxe2x80x9d are brought into contact with the connecting members 2. A voltage is applied to the control pins xe2x80x9ccxe2x80x9d of the electronic part xe2x80x9cgxe2x80x9d via the connector xe2x80x9cfxe2x80x9d in a state that each test pin xe2x80x9cdxe2x80x9d is short-circuited by the connecting member 2 that is short-circuited via a short-circuit layer xe2x80x9ckxe2x80x9d of the testing substrate xe2x80x9cexe2x80x9d and the pad xe2x80x9cixe2x80x9d. In this way, an electrical continuity (breakage) test of the pins xe2x80x9cdxe2x80x9d is carried out (a test state at step 2).
FIG. 14 shows a structure of a conventional probe that secures a connecting member within the adapter xe2x80x9cnxe2x80x9d. Caulks 4a and 4b are provided in a cylinder 4 that secures a connecting member 3. A movable portion 3b of the connecting member 3 and a movable portion 3c on the side of the contact portion 3a are disposed between the caulks 4a and 4b. Further, a coil spring 5 is disposed in a compressed state between the movable portions 3b and 3c. When the connecting member 3 is pressed downward, the connecting member 3 moves within a movable range. The connecting member 3 and the contact portion 3a are brought into contact with the pin of the electronic part and the pad of the testing substrate while being urged by the coil spring 5.
In the conventional positional mechanism of the adapter as shown in FIG. 11 to FIG. 13, there is no problem if the number of pins to be tested is small. However, when a large electronic part has a large number of pins like a few thousand terminals, for example, 3,000 terminals, it is difficult to ensure high precision in the positioning member that fixes the electronic part and supports this large number of pins. Further, it is also difficult to ensure high precision in the position of the position member that positions the adapter.
There may be considered a method of carrying out the above test at step 1 and the test at step 2 by using two separate adapters so that each adapter carries out an exclusive test. However, the use of the two kinds of adapters increases the cost of the adapters. Further, as the test is not finished at one time and is carried out at two divided times, the process of setting up the short-circuit test and the current conduction test increases. As a result, it takes a long time for the tests, which is not desirable.
Further, when the probe has such a structure that the portion for securing the connecting member is integrated with the connecting member, the cost of a connecting member for carrying out the test increases in the case of a large electronic part that has a few thousand test pin terminals. This leads to an increase in the cost of the adapter and the testing apparatus. Further, in the probe structure as shown in FIG. 14, the caulks are formed at two positions in the state that the movable portion of the connecting member and the coil spring are accommodated in the cylinder. Therefore, this results in a complex structure of the cylinder, and the cost of the members further increases.
Further, in the case of electrical connection between the electronic part and the testing substrate as described above, and also generally in the case of electrical connection between an electronic part and a substrate or between an electronic part and another electronic part, a secure electrical connection is always required. Further, a simple structure, not involving a high cost and providing ease of maintenance, is also required.
It is a first object of the present invention to provide an electronic part testing apparatus capable of securely carrying out an electrical connection between an electronic part and a testing member at the time of testing a connectability of a wiring pattern of the electronic part.
It is a second object of the present invention to provide an electronic part testing apparatus capable of successively carrying out a plurality of tests by using the same apparatus without using a positioning member for fixing an electronic part and positioning a large number of pins.
It is a third object of the present invention to provide an electric connecting member capable of securing an electrical connection between an electronic part and a testing member and further capable of securing an electrical connection between an electronic part and a substrate or between an electronic part and another electronic part in general by using the above electronic part testing apparatus with a low cost simple structure.
In order to achieve the above object, the present invention provides an electronic part testing apparatus for testing a connectability of a wiring pattern of an electronic part having a plurality of terminals. The electronic part testing apparatus comprises: a testing, member having an electrical connection pattern, the electrical connection pattern being electrically connected to the terminals of the electronic part for the test; an adapter positioned between the electronic part and the testing member and establishing an electrical connection between the terminals and the electrical connection pattern when the electronic part is mounted on the adapter for the test. In this case, when the electronic part is pressurized against the adapter for carrying out the electrical connection, the adapter can move in this pressing direction.
In this electronic part testing apparatus, at the time of electrically connecting the terminals of the electronic part to be tested to the tester member, when the electronic part is pressed down, the terminals are pressed against the adapter and an electrical connection of the terminals with the adapter is established. Further, the whole adapter is pressed while moving toward the testing member. Therefore, it is possible to obtain a more secure electrical connection between the adapter and the testing member. Thus, it is possible to securely carry out the test of the electronic part.
In this case, it is preferable that an elastic member is disposed between the adapter and the testing member. With this arrangement, the electronic part can be pressed against the adapter smoothly and securely. Further, the adapter and the testing member can be electrically connected more securely. When the pressure is cancelled, the original state is easily obtained based on the restoring force of the elastic member, which is convenient for proceeding to the next test process. Further, there may be further provided a guide member that is fixed to the testing member and is engaged in a hole formed in the adapter. The adapter may be supported by the guide member in the hole, and may be movable along the guiding member in the pressing direction and in the opposite direction. With this arrangement, the adapter can move in the pressing direction and in the opposite direction while being supported by the guide member.
In a further aspect of the invention, there is provided an electronic part testing apparatus for testing a connectability of a wiring pattern of an electronic part having a plurality of terminals. The electronic part testing apparatus comprises: a testing member having an electrical connection pattern, the electrical connection pattern being electrically connected to the terminals of the electronic part for the test; and an adapter positioned between the electronic part and the testing member and establishing an electrical connection between the terminals and the electrical connection pattern when the electronic part is mounted on the adapter for the test. In this case, the terminals include a plurality of first terminals and a plurality of second terminals. For carrying out the electrical connection, the adapter accommodates first connecting members in holes corresponding to the first terminals so that terminal contact surfaces of the first connectors are positioned within the holes, and accommodates second connectors within holes corresponding to the second terminals so that terminal contact surfaces of the second connectors are positioned within the holes. Further, the terminal contact surfaces of the first connecting members within the holes are located at a position higher than the terminal contact surfaces of the second connectors within the holes.
In this electronic part testing apparatus, the terminal contact surfaces of the first and second connecting members do not project above the adapter, and are within the holes of the adapter. It is possible to mount the electronic part in the adapter so that the terminals can enter the holes at the time of carrying out the test. Therefore, it is not necessary to particularly position the electronic part in the adapter. Thus, a positioning member that has been conventionally required is not necessary. As a result, the apparatus can be provided with a simple structure and with a smaller number of parts. This makes it possible to achieve a reduction in the cost of the apparatus. Further, the terminal contact surfaces of the first connectors are located at a position higher than the terminal contact surfaces of the second connecting members. The electronic part is mounted on the adapter and is pressed against the adapter. In this state, it is possible to carrying out the test in a state that the first terminals (for example, the control pins) are brought into contact with the first connecting members, and the second terminals are not brought into contact with the second connecting members. Thereafter, when the electronic part is further pressed, the second terminals (for example, the test pins) are brought into contact with the second connecting members. It is possible to carry out a next test in this state. In this manner, it is possible to successively carry out the tests at two stages without using a positioning member unlike the conventional practice.
In this case, it is possible to structure the apparatus in a similar manner to that described above such that, when the electronic part is pressed against the adapter for carrying out the electrical connection, the adapter can move in this pressing direction. With this arrangement, the electrical connection between the adapter and the testing member becomes more secure.
Further, it is preferable that each of the first and second connecting members are divided into an upper part and a lower part. Each connecting member includes a terminal contact surface for a contacting the terminals, an electronic part contact portion for contacting a conductive surface connected to the electrical connection pattern of the testing member, and an elastic member disposed between the terminal contact portion and the testing member contact portion. Further, it is preferable that at least one of the first connecting members and the second connecting members are accommodated within straight conductive pipes together with the elastic members. Based on this structure, it is easy to move the terminal contact portion by pressing the terminal, which makes it easy to carry out the tests at two stages. It is also possible to dispose the terminal contact portion and the testing member contact portion by pressing these against the electronic part and the testing member with the elastic member. This makes it possible to obtain a more secure electrical connection, which is preferable.
Further, as the straight pipe is used as described above, each connecting member has a simple structure as compared with the conventional probe structure having caulks. Thus, the number of parts and the number of assembling processes can be reduced, which makes it possible to reduce the cost of adapter parts for carrying out an electric connection. As the cost of connecting members that are the main parts of the adapter can be reduced, the total cost of the testing apparatus can be reduced. Further, as the pipe is provided, the friction between the connecting members and the inner wall surface of the pipe becomes less. As a result, the connecting members can be moved smoothly, and the tests at two stages can be carried out smoothly. An electrical connection between the terminal and the connecting member becomes more secure. It is preferable that the clearance is made smaller in at least a part of each connecting member and the pipe, to have electric conduction. The pipe can be disposed in one or both of the first and second connecting members. It is preferable that the first connecting members, the second connecting members and the elastic members are made of metal, respectively. It is also preferable that these members are provided with a conductive surface treatment. This makes it possible to obtain more satisfactory electrical conduction. The surface treatment may be provided on the front surface of each member, or may be provided on a part of the contact portion or the like. Further, it is preferable that the conductive pipe is constructed of a metal material or a metal material or a resin material on which a conductive surface treatment has been provided. This makes it possible to obtain a further satisfactory electrical conduction.
Further, it is preferable that a connecting member securing member is provided on the top surface of the adapter, and this connecting member securing member can be separated from the adapter. It is also preferable that the terminal contact portion and the testing member contact portion have enlarged portions which are accommodated within the pipe, and when the connecting member securing member is fixed to the adapter, the enlarged portions and the pipe are held within the adapter. With this arrangement, it is possible to secure the connecting members and the pipe within the adapter in a simple structure. Further, as it is possible to inspect and exchange the connecting members by only separating the connecting member securing member, the exchange of the connecting members can be carried out in a satisfactory work condition. This also facilitates the maintenance of the adapter. Further, as only the connecting member securing member can be separated from the adapter, it is possible to carry out the maintenance of the connecting members in a state that the adapter is positioned and fixed to the testing member.
Further, it is preferable that a knurl is formed on at least one of the terminal contact surface on which the terminal contact portion is in contact with the terminal and the testing member contact surface on which the testing member contact portion is in contact with the conductive surface. With this arrangement, it is possible to obtain an electrical connection more securely. Particularly, even when the other contact surface is a solder portion and the surface of this portion has been oxidized, it is possible to obtain a satisfactory contact state. It is preferable that the pitch of the projections of the knurl is about 0.2 mm, and it is more preferable that the pitch is about 0.1 mm. It is also possible to provide a conductive surface treatment on the inner wall surface of the hole within the adapter for accommodating at least one of the first connecting members and the second connecting members. With this arrangement, it is possible to obtain a further satisfactory electrical conduction and to omit the conductive pipe. This makes it possible to avoid the need of pipe parts and to simplify the assembling. Further, it is preferable that a first mask having a plurality of holes corresponding to a plurality of terminals to be tested among the plurality of terminals of the electronic part is provided at a side of the adapter where the electronic part is disposed. The terminals of the electronic part also include terminals that are not to be tested. However, even when holes are provided on the adapter corresponding to all the terminals, holes that are not necessary for the test can be closed as the first mask does not have holes corresponding to the terminals that are not to be tested. With this arrangement, it is possible to prevent in advance abnormal materials from invading the adapter from the unnecessary holes. Further, it is preferable that a second mask having a plurality of holes corresponding to each hole of the first and second connecting members of the adapter is disposed at the testing member. As it is possible to carry out the positioning with respect to the testing member by utilizing the holes of the second mask, it becomes easy to position the adapter and the tester member.
Further, according to a still further aspect of the invention, there is provided an electronic part testing apparatus for testing a connectability of a wiring pattern of an electronic part having a plurality of terminals. The electronic part testing apparatus comprises: a testing member having an electrical connection pattern, the electrical connection pattern being electrically connected to the terminals of the electronic part for the test; an adapter positioned between the electronic part and the tester member and establishing an electrical connection between the terminals and the electrical connection pattern when the electronic part is mounted for the testing. In this case, the terminals include a plurality of first terminals and a plurality of second terminals. For carrying out the electrical connection, the adapter includes first connecting members corresponding to the first terminals and second connecting members corresponding to the second terminals. The testing member includes through-holes provided corresponding to the first and second connecting members, respectively, and having on the inner wall surfaces conductive layer connected to the electrical connection pattern, and a testing member connecting member disposed within each through-hole to contact the conductive layer. Thus, the testing member connecting member has a contact with the first and second connecting members, respectively, to execute the electrical connection.
According to this electronic part testing apparatus, the conductive layer provided within the through-hole of the testing member is connected to the electrical connection pattern, and the connecting member is brought into contact with the conductive layer. Therefore, the connection route can be reduced, which becomes advantageous for a high-speed testing. By dividing the testing member connecting member into the two of the upper and lower parts, and by disposing the elastic member into between these two connectors, the electrical connection with each connecting member becomes more secure.
At least one of the first connecting members and the second connecting members can be structured by conductive vessels each having an opening into which the terminal can enter and a conductive medium filled in the vessel. This arrangement can more simplify the structure of the connecting members, and can reduce the number of connecting member parts. It is also possible to achieve a reduction in the total cost of the adapter. As the conductive medium, there can be used a known conductive powder, conductive liquid, conductive particle, fine-cut conductive fiber, particle-shaped conductive rubber, or the like. The conductive medium is not limited to the above. It is preferable that a gap is formed between the electronic part and the top surface of the adapter so that the surface of the electronic part does not contact the top surface of the adapter when the electronic part is disposed on the adapter for pressing the electronic part. With this arrangement, when the electronic part is mounted on the adapter and is pressed, the risk of a disconnection of the wiring pattern near the root of each pin of the electronic part can be avoided. A stress applied to the root of the pin can also be avoided, by preventing the terminal roots of the electronic part from hitting against the surface of the adapter.
Further, according to still another invention, there is provided an electric connector comprising: a first contact portion for having a contact with a first external contact portion; a second contact portion for having a contact with a second external contact portion; an elastic member disposed between the first contact portion and the second contact portion; and a straight-shaped pipe for accommodating therein the first contact portion, the second contact portion and the elastic member. In this case, the first contact portion and the second contact portion are electrically connected.
According to the electric connecting member of the present invention, the electric connecting member is disposed between a substrate and an electronic part for providing an electrical connection between these units or is disposed between an electronic part and another electronic part for providing an electrical connection between these electronic parts, not only for an electrical connection in the adapter. Therefore, it is possible to provide a secure electrical connection between the two units in a simple structure. This avoids the need for wiring and soldering, and facilitates both the exchange of parts and the maintenance. In order to obtain a more satisfactory electrical connection between the first contact portion the second contact portion, it is effective to provide a conductive surface treatment on each of these members.